Toasted Coconut Cake with Key Lime Filling
Is this the most complicated cake I’ve made in a long time, possibly ever?
Yes.
Is it completely and utterly worth it?
Also yes.
Lucky folks have heard me rave about this dessert, and even luckier folks got to taste it. The cake itself is toasty, caramel-y, and rich from the brown butter/coconut cream/toasted white chocolate combo. The filling has just enough tang to balance out the crumb and leave you wanting more. The frosting? Don’t get me started on the frosting. I put that shit on everything.
This cake will take you most of the day to make, so block out your Sunday and invite some guests.
Special thanks to Binging with Babish for the initial cake recipe and Buttermilk by Sam for the lime curd recipe and white chocolate toasting method. This monster of a cake would not have been possible without you.
Note: This recipe is measured in grams. You will need a scale; measuring this whole thing by volume is way too complicated. Additionally, I didn’t use actual key limes because I would have had to juice SO MANY, but you are welcome to.
Ingredients
The batter:
225g browned butter (see notes)
50g coconut cream
400g granulated sugar
4 eggs
115g toasted white chocolate (see notes)
360g all-purpose flour
2 tsp salt, or more to taste
1 tsp baking powder
½ tsp baking soda
160g coconut milk, shaken to re-combine
100g sour cream
1 tsp vanilla
The filling:
67g granulated sugar
2 (key) limes, zested
80g freshly squeezed lime juice, about 3 regular or 10+ key limes-worth
2 large eggs
½ tsp sea salt, or more to taste
38g butter, cold and cubed
The frosting:
450g (2 packages) cream cheese, room temperature
225g (2 sticks) butter, room temperature
200g—350g powdered sugar, to taste
1tsp vanilla
1tsp salt
Splash of vinegar, to taste
150g shredded coconut, toasted (see notes)
Ingredient Notes/Preparation
Browning butter
For a more in-depth explanation, Food Network has a pretty good guide.
Over medium heat, melt 225g (2 sticks) of unsalted butter in a small saucepan.
Cook the butter, swirling often and stirring occasionally, until the milk solids in the butter turn brown and the butter smells nutty and toasty.
Measure the new weight of the browned butter. To cool it to room temperature and replace any moisture lost during browning, add ice cubes until the butter-ice mixture once again weighs 225g.
Whisk the ice into the butter until fully combined. Use in place of butter in any recipe.
Toasting white chocolate
For a more in-depth explanation, see Buttermilk by Sam’s recipe.
Preheat your oven to 250˚F.
Spread 200g or so high-quality white chocolate onto a clean baking pan. I prefer to have more, rather than less, because I enjoy snacking. If you’re looking to make just enough for this recipe, 200g should be close to the right amount.
Bake for 10 minutes.
Mix and smooth the white chocolate with a rubber or offset spatula. Return to the oven.
Continue baking and smoothing in 10-minute intervals until golden brown. The chocolate will become sandy and bumpy — do not fear!
Blend the toasted white chocolate in a food processor until smooth and creamy.
Leave warm for this recipe, or cool in blocks for future enjoyment.
Toasting shredded coconut
Preheat oven to 325˚F
Spread the shredded coconut in a thin layer on a baking sheet.
Bake 5-15 minutes, stirring occasionally for even toasting.
Set aside.
Method
The batter:
Preheat your oven to 325˚F. Line the bottom of a 9” cake pan (preferably 3” tall) or bundt pan with parchment paper.
In one bowl, whisk together the all-purpose flour, salt, baking powder, and baking soda. These are your dry ingredients.
In a second bowl, combine the coconut milk, sour cream, and vanilla. These are your wet ingredients.
In a third bowl (large enough to eventually hold all the ingredients) beat together the browned butter, coconut cream and granulated sugar until light and fluffy, about 4-6 minutes.
Add the eggs and toasted white chocolate to the sugar-butter mixture. Enjoy mixing; it’s hard to over-mix at this stage.
Add the dry and wet ingredients to your third bowl, alternating dry-wet-dry-wet-dry. Be careful not to over-mix!
Add any additional salt to taste. You don’t want the batter to taste too savory, but additional salt balances some of the richer, sweeter flavors.
Bake for 50-70 minutes, or until a toothpick comes out clean. Let cake cool completely in the pan before turning out.
The filling:
For a more in-depth explanation, see Buttermilk by Sam’s recipe.
Prepare a double boiler: boil water in a pot and set an empty metal bowl on top. This method cooks the curd with a gentle, indirect heat so it is less likely to curdle or burn.
Massage together the sugar and lime zest in the metal bowl (off heat) until the sugar becomes the texture of wet sand.
Whisk in the eggs and lime juice.
Place the bowl over the pot of boiling water. Cook, whisking frequently, until the curd thickens enough to coat the back of a spoon. You know it’s cooked when you can run your finger down the back of the spoon and the curd remains in place.
Strain the curd through a sieve and whisk in the cold butter. Add any additional salt to taste. Let cool completely before using.
The frosting:
Whisk together the cream cheese, butter, salt, and vanilla until smooth.
Sift and whisk the powdered sugar into the mixture. The final amount depends on humidity and personal preference — you are looking for a frosting that is slightly tangy and relatively thick. The more sugar you add, the thicker and grainier the mixture will become.
Add any additional salt and/or vinegar to taste.
Save the toasted coconut for our next and last step: assembly!
Assembly
Remove your cooled cake from its pan. I like to run an offset spatula around the edge, and the cake tends to pop right out.
Cut the cake in half into two layers. If its top has domed significantly, you can cut a little off the top to make the cake more cylindrical. The top is usually a little crunchy, which is delicious.
Pipe a ring of frosting onto the bottom cake layer. This frosting fence will contain your filling so it doesn’t all ooze out. Spoon and spread the lime filling into this circle.
Place the next cake round on top of the first, and spread a thin layer of frosting on the entire cake. This will be our crumb coat. Do not use all the frosting!
Chill the cake until the frosting has set and is no longer tacky.
Spread the rest of the frosting onto the cake.
Take a handful of toasted coconut and press it into the sticky frosting. Cover as much cake as you can.
Serve. Enjoy. Savor the fruit of your labor.
